The main theme of the article is sect studies in USSR. Soviet tradition in the fi eld did not appear from the thin air but was a «dialectic» — in the sense that simultaneously and legitimately can be estimated as continuation and rejection — sequel of pre-Soviet sect-study approach. Soviet tradition per se is based on ambiguous — according to Lenin’s position — understanding of sectarianism as an example of class combat (positive dimension) but religiously specific (negative dimension). This negative attitude was expressed in specific ideological and political position towards sectarianism. Stating this position was a priority and that is why the establishing of proper Soviet scientifi c approach was problematic. It began to form only in the 1960-s. The term «sect» for both pre-Soviet and Soviet researches had negative connotation in dogmatic way for the former and in ideological way for the latter. Such a long history of negative understanding of the term makes it very hard to understand it as a neutral in contemporary Russia.